From Muppet Wiki

Michael Chang (b. 1972) is a former professional tennis player from the United States. He is best remembered for becoming the youngest-ever male winner of a Grand Slam singles title when he won the French Open in 1989 at the age of 17. Chang published a book about his career, Holding Serve: Persevering On and Off the Court, in 2002. He retired from the sport in 2003.

Chang appeared on Sesame Street in several inserts, including one with Zoe, and another Big Bird, in which they play tennis together and tie their shoes (EKA: Episode 3974). Chang also appeared in the celebrity version of "A New Way to Walk."